Method and mechanism for operating the locking means for chill plate of a rigid starter bar

ABSTRACT

A method and mechanism for operating the locking means for the chill plate of a rigid starter bar in a continuous-casting machine. The mechanism includes a cam on the wall of the pit which receives the basket hoist for the starter bar and a cooperating actuating lever pivoted to the hoist. The mechanism enables the starter bar to remain in contact with the hoist throughout the operating cycle, and assures that the leading end of the casting always is at the same level when the starter bar is disconnected.

' United States Patent Cuscino Nov. 4, 1975 METHOD AND MECHANISM FOR 3,520,351 7/1970 Rankin 164/274 3,528,486 9/1970 Golde 164/274 OPERATING THE LOCKING MEANS FOR CHILL PLATE OF A RIGID STARTER BAR Thomas A. Cuscino, Scott Township, Allegheny County, Pa.

Assignee: United States Steel Corporation,

Pittsburgh, Pa.

Filed: Aug. 2, 1974 Appl. No.: 494,244

Inventor:

References Cited UNITED STATES PATENTS 8/1967 Foldessy 164/282 X 6/1969 Gallucci 164/274 Primary Examiner-Francis S. Husar Assistant ExaminerJohn S. Brown Attorney, Agent, or FirmWalter P. Wood [57] ABSTRACT starter bar to remain in contact with the hoist through- 1 out the operating cycle, and assures that the leading end of the casting always is at the same level when the starter bar is disconnected.

4 Claims, 4 Drawing Figures US. Patent Nov. 4, 1975 Sheet 1 of 2 3,916,980

US. Patent Nov. 4, 1975 Sheet 2 of2 4 4 4 4 0 w oo @%W@OOOLvO W ,J D 000 a E@@@@O g METHOD AND MECHANISM FOR OPERATING THE LOCKING MEANS FOR CHILL PLATE OF A RIGID STARTER BAR This invention relates to an improved method and mechanism for operating the locking means for the chill plate of a rigid starter bar in a continuous-casting machine.

In continuous-casting machines which utilize a rigid starter bar, conventional practice is to catch the descending bar in a basket hoist as it is disconnected from the leading end of the casting and lower it out of the way. Before the next cast begins, a detachable chill plate is installed on the upper end of the bar, and the hoist and bar are lifted to position the chill plate within the mold thereabove. When the starter bar subsequently is disconnected, the chill plate stays with the casting. Reference can be made to Gallucci US. Pat. No. 3,448] 89 of common ownership for a showing of a rigid starter bar, disconnect means, and a basket hoist of the type to which the present invention relates and over which the present invention is an improvement.

In the known apparatus, such as the Gallucci patent shows, the locking means for the chill plate includes a rod which extends through a vertical passage in the body of the starter bar and which carries a plunger at its lower end. Soon after the beginning of a cast, as the descending starter bar reaches the basket hoist, the

plunger contacts the bottom of the hoist and pushes the rod upwardly relative to the body of the bar. The upper end of the rod is connected to a linkage at the top of the body, which linkage acts to release the chill plate on such contact.

The known operating mechanism for the locking means has certain disadvantages. The starter bar does not remain in contact with the hoist at all times. When the starter bar is lifted at the beginning of a cast, it is picked up by power driven pinch rolls of the casting machine. The pinch rolls lift the bar off the hoist and propel it to its final position for beginning a cast. If for any reason the starter bar is allowed to drop, the parts may be damaged. Modem low head casting machines have only a single set of pinch rolls. If these are opened inadvertently, the bar of course drops. Another difficulty is that the hoist is not necessarily always at the same height when the descending starter bar contacts it. Hence the level of the leading end of the casting at the moment the starter bar is disconnected varies from cast to cast. This is of little consequence in some installations which have two or more sets of power driven pinch rolls engaging the starter bar at spaced-apart levels. In such installations it is necessary only that the leading end of the casting lies somewhere between the sets of pinch rolls at the moment of disconnect. Low head installations, which have only a single set of pinch rolls, operate properly only if the leading end of the casting is always at the same level when the starter bar is disconnected.

An object of the present invention is to provide an improved method and mechanism for operating the locking means for the chill plate of a rigid starter bar in which I overcome the foregoing difficulties, that is, in which the starter bar may remain in contact with the hoist throughout the operating cycle, and in which the leading end of the casting always is at the same level when the starter bar is disconnected.

A further object is to provide an improved method and mechanism for accomplishing the foregoing object 2 in which the basket hoist carries a cam-operated actuating lever for operating the locking means.

IN THE DRAWINGS:

FIG. 1 is a top plan view of a basket hoist and starter bar equipped with an operating mechanism constructed in accordance with my invention;

FIG. 2 is a vertical section on line IlII of FIG. 1;

FIG. 3 is a diagrammatic side elevational view showing the relation of parts with the basket hoist fully lowered before a cast is to begin; and

FIG. 4 is a view similar to FIG. 3, but showing the relation of parts with the hoist and starter lifted in preparation to begin a cast.

FIG. 1 shows in plan a portion of a pit 10 which is located beneath a continuous-casting machine and receives a basket hoist 12 carrying a starter bar 13. The walls at two opposed faces of the pit carry guides 14. Rollers 15 are joumaled to the hoist at its ends and ride against these guides. The upper face of the hoist has eye bolts 16 or equivalent adjacent each end to which ropes 17 are attached for lifting and lowering the hoist and starter bar.

As shown in FIG. 2, the starter bar 13 includes a body 19 which has a vertical passage 20. A rod 21, which forms part of the locking means, is housed for vertical movement within this passage.- The upper end of the starter bar has a linkage to which rod 21 is connected for locking a chill plate 24 (shown in the diagrammatic views of FIGS. 3 and 4) to the bar. Preferably the linkage is of similar construction to that shown in the aforementioned Gallucci patent; hence the showing is not repeated. When rod 21 is in a raised position with respect to the body 19 of the bar, the chill plate is released and can be freely installed or removed. When the rod is lowered, the chill plate is locked to the bar.

In accordance with my invention, the wall at the broad face of pit 10 carries a cam track 25, best shown in the diagrammatic views of FIGS. 3 and 4. The major portion of the cam track has a straight vertical surface, but the upper end portion is inclined, as indicated at 26. The cam track normally is stationary, but its position can be adjusted vertically. The basket hoist 12 carries a pair of horizontally spaced brackets 27, between which an actuating lever 28 is pivoted on a pin 29 (FIGS. 1 and 2). Lever 28 is of inverted L-shape in outline, having an approximately vertical depending arm 30 to which a roller 31 is joumaled and an approximately horizontal counterweighted arm 32. Roller 31 rides against the cam track 25 and thus serves as a cam follower. The lower end of the body 19 of the starter bar has a cutout 33 into which arm 32 extends. The lower end of rod 21 bears against the upper face of arm 32. When roller 31 abuts the straight vertical portion of the cam track 25, the lever 28 holds rod 21 in a relatively raised position in which the chill plate is released. When roller 31 is clear of the straight vertical portion of the cam track, lever 28 rotates clockwise and allows rod 21 to move to its relatively lowered position in which the chill plate is locked to the bar.

As shown in the diagrammatic views of FIGS. 3 and 4, a pair of sheaves 39 are joumaled to a suitable support above pit 10. The ropes 17 of the hoist 12 extend over the sheaves and down to the basket. A chill-plate maintenance platform 40 is situated above pit 10 djacent the position which the upper end of the starter bar 13 occupies when the bar is in its lowermost position in the pit. Above the platform are the various rolls 41 of 3 the casting machine, including power driven pinch rolls 42 and a switch section 43. Above the rolls is an openended mold 44. The casting machine itself can be conventional and hence is not shown in detail.

FIG. 3 shows the hoist 12 and starter bar 13 in their lowermost position, which they occupy while a casting operation is taking place. Roller 31 abuts the straight vertical portion of the cam track 25, the position in which the chill plate 24 is released. FIG. 4 shows the hoist and starter bar lifted in preparation to begin a cast. Roller 31 has cleared the cam track, the position in which the chill plate is locked to the starter bar. Subsequently, as the hoist and starter bar descend as the casting operation gets underway, roller 31 abuts the inclined portion 26 of the cam track and rotates counterclockwise to release the chill plate and thus disconnect the starter bar from the leading end of the casting.

According to my operating method, the starter bar remains in contact with the hoist throughout its operating cycle. If the pinch rolls 42 of the casting machine inadvertently release the starter bar, the hoist continues to provide support and the bar does not drop. Since the roller 31 always engages the inclined portion 26 of the cam track 25 when the starter bar is at the same height, the leading end of the casting always is at the same level when the starter bar is disconnected. The actual location of this level can be adjusted by adjusting the position of the cam track up or down.

I claim:

1. In a combination which includes a rigid starter bar, a chill plate supported by said starter bar, a vertically movable hoist on which said bar rests and is supported thereby, and means for receiving said hoist and bar when lowered, said bar having locking means for said plate movable between released and locked positions,

an improved mechanism for operating said locking means, said mechanism comprising cooperating means on said hoist and on said receiving means for releasing said locking means at a fixed location as said hoist and starter bar descend as a casting operation gets underway, whereby said starter bar remains on said hoist throughout the operating cycle and said starter bar is always at the same height when the chill plate is re leased.

2. A combination as defined in claim 1 in which said cooperating means includes a cam carried by said receiving means, an actuating lever pivoted to said hoist and engaging said locking means, and means on said lever engagable with said cam for pivoting said lever.

3. A combination as defined in claim 2 in which said cam includes a track, the major portion of which is straight and vertical, but which has an inclined portion at its upper end, the means on said lever pivoting said lever to lock or unlock the chill plate when passing over said inclined portion.

4. A method of operating the locking means for the chill plate of rigid starter bar, wherein the bar is carried in a vertically movable basket hoist when disconnected from the chill plate at the beginning of a cast, lowered for storage and lifted by said hoist to begin a cast, said method comprising actuating said locking means to release the chill plate by the action of cooperating means on said hoist and fixed means alongside said hoist when the starter bar descends at the beginning of a cast, maintaining the starter bar in contact with the hoist throughout the operating cycle, and performing the step of actuating the locking means with the starter bar always at the same height. 

1. In a combination which includes a rigid starter bar, a chill plate supported by said starter bar, a vertically movable hoist on which said bar rests and is supported thereby, and means for receiving said hoist and bar when lowered, said bar having locking means for said plate movable between released and locked positions, an improved mechanism for operating said locking means, said mechanism comprising cooperating means on said hoist and on said receiving means for releasing said locking means at a fixed location as said hoist and starter bar descend as a casting operation gets underway, whereby said starter bar remains on said hoist throughout the operating cycle and said starter bar is always at the same height when the chill plate is released.
 2. A combination as defined in claim 1 in which said cooperating means includes a cam carried by said receiving means, an actuating lever pivoted to said hoist and engaging said locking means, and means on said lever engagable with said cam for pivoting said lever.
 3. A combination as defined in claim 2 in which said cam includes a track, the major portion of which is straight and vertical, but which has an inclined portion at its upper end, the means on said lever pivoting said lever to lock or unlock the chill plate when passing over said inclined portion.
 4. A method of operating the locking means for the chill plate of rigid starter bar, wherein the bar is carried in a vertically movable basket hoist when disconnected from the chill plate at the beginning of a cast, lowered for storage and lifted by said hoist to begin a cast, said method comprising actuating said locking means to release the chill plate by the action of cooperating means on said hoist and fixed means alongside said hoist when the starter bar descends at the beginning of a cast, maintaining the starter bar in contact with the hoist throughout the operating cycle, and performing the step of actuating the locking means with the starter bar always at the same height. 